Cutting balloon assembly and method of manufacturing thereof

ABSTRACT

A cutting balloon assembly and a method for fabrication of the assembly is described. The cutting balloon assembly comprises a delivery catheter, an expandable balloon mounted on the catheter distal end, and a scoring mesh disposed around the expandable balloon. The scoring mesh comprises interlacing filaments that extend from a mesh proximal end towards a mesh distal end, form distal filament loops at said mesh distal end, and then return to the mesh proximal end. At least a part of the interlacing filaments forms one or more permanent links with neighboring filaments between the mesh proximal end and the mesh distal end.

FIELD OF THE INVENTION

This invention relates generally to medical devices and moreparticularly to angioplasty balloon devices for expanding passageways inthe venous system.

BACKGROUND OF THE INVENTION

One of the most common heart diseases is atherosclerotic cardiovasculardisease, caused by the buildup of lesions or plaque on the inside wallof blood vessels. For example, a variety of lesions may occur related toatherosclerosis, including aorto-ostial lesions. Aorto-ostial lesionsdamage the ostium of the main blood vessels branching from the aorta.This can result in a partial, or even complete, blockage of the artery.As a result of the danger associated with such a blockage, severalmethods and procedures have been developed to treat arterial blockages.

One such method is an angioplasty procedure which uses an inflatableballoon to dilate the blocked artery. Angioplasty procedure involves theuse of a dilatation balloon catheter. The balloon catheter is advanced,using fluoroscopy, over a guidewire so that the balloon is positionedadjacent a stenotic lesion. The balloon is then inflated inside astenosed region in a blood vessel in order to apply radial pressure tothe inner wall of the vessel and widen the stenosed region to enablebetter blood flow.

The efficacy of the dilation of a stenosis can be enhanced by incisingthe material that creates the stenosis. Consequently, angioplastyballoons with scoring elements, such us cutting edges, atherotomes orblades mounted on the surface of the balloon were proposed, which areintended to incise a stenosis during the dilation procedure. The cuttingballoons can also be used to break through or scrape plaque andstenoses.

For example, U.S. Pat. No. 5,196,024 to Barath et al. describes a deviceand method for dilation or recanalization of a diseased vessel by use ofa balloon catheter with cutting edges to make longitudinal cuts in thevessel wall. The diameter of the vessel can be increased withoutsubsequent secondary cellular proliferation or restenosis in the vesselcaused by angioplasty methods.

U.S. Pat. Pub. No. 2004243156A to Show-men et al. and U.S. Pat. No.7,291,158 to Bence et al. describe various angioplasty balloon cathetersand methods of making and using the same. The balloon catheters includea catheter shaft and a balloon coupled to the shaft. The ballooncatheters include one or more cutting edges, blades or wings coupled tothe balloon.

One of the drawbacks of the prior art cutting balloons equipped withcutting edges or blades is associated with the fact that these devicestend to be fairly stiff. This has the affect of limiting the flexibilityand deliverability of the balloon as it is advanced through the tortuousconfines of a vessel or other body lumens. Moreover, the cuttingballoons equipped with cutting blades and edges can be difficult todeflate and collapse. This can make removal of the balloons from thevasculature more difficult than the removal of corresponding angioplastyballoons which do not include stiff cutting blades. Additionally, it wasfound that the cuts imparted by such cutting balloons do not alwaysprovide the dilatation and treatment of fibrotic lesions as would bedesired.

Angioplastic balloons that employ a woven mesh, cutting strings or wiresare also known. These balloons are proved to be more flexible and saferthan the balloons employing cutting blades and edges.

For example, U.S. Pat. Pub. No. 2006/259005A describes an angioplastydilatation device provided with scoring elements which may incorporate adrug to be delivered to a body lumen, typically a blood vessel. Thescoring elements can, for example, be in the form of a single wire or aplurality of wires wrapped around a dilatation balloon in a helicalconfiguration.

U.S. Pat. Pub. No. 2007/198047A describes a cutting balloon catheterassembly including a catheter equipped with an inflatable balloon havingan interior cavity and an expandable covering disposed about theballoon. The expandable covering is in the form of a mesh coating havinga cross-hatched pattern. The mesh coating is made of plastic or metalfibers, where some of the fibers have cutting edges. In operation, thecutting edges abrade the stenoses, plaque or lesions along the vesselwalls, when the catheter assembly is reciprocally moved longitudinallyor rotationally after inflation of the balloon.

A coronary stenting procedure is known in the art for treatment ofaorto-ostial lesions. An incomplete apposition between the stentfilaments and the arterial wall can increase the risk of an embolicsource as a result of the stagnation of the blood flow in the deadspace. A strong compression of the vessel wall on the opposite side ofthe unattachment at the stent edge because of the straightening effecton tortuous vascular curves may induce a kink in the artery that thuscould possibly cause edge restenosis. It is also recognized in the artthat incomplete expansion of the stent as compared with a predefinedreference (stent underexpansion) can result in calcification, whichsignificantly increases the subsequent risks of restenosis and/or stentthrombosis.

Systems and methods are known that provide stent visualization incoronary arteries, and provide analysis tools based on enhancedangiograms (of the deployed stent). Such analysis can provideinformation on the success of the stent deployment. Based on theenhanced image the physician can decide whether the procedure wascarried out satisfactory or might also decide to further dilate ordeploy another stent. The shortcoming of all those systems and methodsis that they are providing information only after stent deployment.

SUMMARY OF THE INVENTION

There is a need in the art to provide a cutting balloon assembly thatwill be more flexible, safer and provide improved dilatation andtreatment of fibrotic lesions.

It would be advantageous to have a cutting balloon assembly equippedwith such a scoring mesh that does not prevent inflation of the balloonand that returns to its original state after deflation of the balloon.

It would be beneficial when a scoring mesh and clamps fastening the meshto the delivering catheter or expandable balloon would have flexibilitysufficient for the cutting balloon assembly to pass through the tortuousconfines of a vessel or other body lumens and do not damage them.

It would also be advantageous to have a scoring mesh made of filamentshaving such a dimension and a shape of the cross-section so as to incisecalcified, fibrotic and other hard stenosed region and to leave scoresand grooves thereon during the dilation procedure. Such grooves mayfacilitate a further positioning of a stent at the scored place.

It would also be beneficial to have a cutting balloon assembly such thatit can a score a relatively large area that may allow the deposition ofa large amount of drugs in the scores.

It would further be advantageous to have a cutting balloon assemblycomprising a scoring mesh built up of drug-eluting filaments to allowcontrolled local release of a drug directly to the injured endothelium,thereby avoiding side effects, such as restenosis.

There is also a need for a device and method that could provideindications and analysis for a sub-optimal deployment before the stentis delivered and deployed. This could assist the physician in selectionof the best treatment and deployment strategy.

Thus, it would be beneficial to have a scoring mesh radiopaque, so as topermit it to be visualized by a fluoroscope during use in anatomy. Theradioopaque scoring mesh can also provide a simulation of a possibledeployed stent, thus providing a possibility for analysis ofsub-optional deployment.

It would further be advantageous to have a scoring mesh which issymmetrical. This feature would enable the operator to maintain thesymmetry of the mesh pattern visualized by a fluoroscope duringangioplasty procedure in order to control the treatment of plaque orstenosis and predict how a stent will further be positioned afterremoval of the cutting balloon catheter from the treated vessel. Thedistortion of the symmetry of the mesh pattern visualized by afluoroscope may indicate the undulations of the inner surface of thevessel and the quality of the angioplasty treatment.

The present invention satisfies the aforementioned needs by providing anovel cutting balloon assembly. The cutting balloon assembly includes adelivery catheter having a catheter proximal end, a catheter distal end,and at least one catheter lumen extending between the catheter proximaland distal ends. The assembly includes also an expandable balloon havinga balloon proximal end and a balloon distal end. The expandable balloonis mounted on the catheter distal end. The assembly further includes ascoring mesh disposed around the expandable balloon. The scoring meshcomprises interlacing filaments that interweave between a mesh proximalend and a mesh distal end. At least a part of the interweaving filamentsintertwines to form at least one permanent link with neighboringfilaments. It should be noted that the expression “interlacing”, as usedfor the purpose of the present description, has a general meaning thatincludes “interweaving” and “intertwining”. The expression“interweaving” for filaments implies passing each of the filaments aboveone or more other filaments and under one or more other filaments,whereas the expression “intertwining” for filaments implies uniting thefilaments by twining one filament with another (e.g., twisting thefilaments together by one or more turns) and/or twining one filamentabout another. Thus, due to the intertwining, at least a part of theinterlacing filaments can form at least one permanent link withneighboring filaments between the mesh proximal end and the mesh distalend.

According to one embodiment of the present invention, the interlacingfilaments form at least distal filament loops at the mesh distal end.According to another embodiment of the present invention, theinterlacing filaments form the distal filament loops at the mesh distalend along with proximal filament loops at a mesh proximal end.

The scoring mesh is connected to the balloon proximal and distal ends.According to one embodiment, the cutting balloon assembly comprises oneor more distal strings that are wound round the balloon distal end. Thedistal strings pass through openings in the distal filament loops,thereby to tie the distal filament loops of the scoring mesh to theballoon distal end.

When the interlacing filaments form also the proximal filament loops atthe mesh proximal end, the cutting balloon assembly can comprise one ormore proximal strings wound round the balloon proximal end. The proximalstrings pass through the openings in the proximal filament loops,thereby to tie the proximal filament loops of the scoring mesh to theballoon proximal end.

According to a further embodiment, the cutting balloon assembly cancomprise one or more distal strings wound round the delivery catheterafter the balloon distal end in relation to an operator using thecutting balloon assembly. The distal string can pass through theopenings in the distal filaments loops, thereby to tie the scoring meshto the delivery catheter.

According to yet an embodiment, the cutting balloon assembly cancomprise one or more proximal strings wound round the delivery catheterbefore the balloon proximal end in relation to an operator using thecutting balloon assembly, thereby to tie the filaments at the meshproximal end to said delivery catheter.

According to an embodiment, the scoring mesh includes scoring elements.The scoring elements can, for example, be formed by twisted turns of theentwined filaments. Likewise, the scoring elements can be certaindedicated elements attached to or placed around the filaments formingthe scoring mesh.

According to an embodiment, the interlacing filaments of the scoringmesh are radiopaque. The radioopaque scoring mesh can also provide asimulation of a possible deployed stent, thus providing a possibilityfor analysis of sub-optional stent deployment.

According to an embodiment, at least a part of the scoring meshcomprises an active pharmacological agent that can inhibit inflammationand smooth-muscle cell growth.

The cutting balloon assembly can comprise a guiding catheter thatincludes a lumen for housing the delivery catheter. The lumen hassufficient size for receiving the distal end of the delivery cathetertherethrough together with the locator unit in a contracted condition.

The cutting balloon can be equipped with one or more guide wires.

The present invention also satisfies the aforementioned needs byproviding a method for fabrication of the cutting balloon assemblydescribed above. The method comprises providing a predetermined numberof filaments having predetermined properties, diameter and length andfabricating a scoring mesh from these filaments. The fabrication of thescoring mesh includes providing a weaving jig having a cylindricalstructure including a plurality of pins disposed circumferentially aboutthe surface of the structure in rows and extending outwardly therefrom.The filaments are placed between the pins and interlaced (i.e.,interweaved and intertwined) with neighboring filaments to form ascoring mesh. The interlacing of the filaments includes interweaving thefilaments between the mesh proximal end and the mesh distal end, andintertwining at least a part of the interlacing filaments to form one ormore permanent links with neighboring filaments. The permanent links canbe formed by twining one filament with another (i.e., twisting thefilaments together by one or more turns) and/or twining one filamentabout another.

The fabrication of the scoring mesh also includes forming distalfilament loops at least at the mesh distal end. When desired, proximalfilament loops can also be formed at the mesh proximal end.

The fabrication of the scoring mesh further includes annealing thescoring mesh.

According to one embodiment, the fabricating of the scoring meshincludes providing scoring elements on the filaments forming the scoringmesh.

According to one embodiment, the fabricating of the scoring mesh furtherincludes providing an active pharmacologic agent within the scoringmesh. The providing of the active pharmacologic agent can includecoating at least a portion of a surface of the filaments with a materialincluding such an agent.

The fabrication of the cutting balloon assembly further includesproviding a delivery catheter. The delivery catheter has a catheterproximal end, a catheter distal end, and at least one catheter lumenextending between the catheter proximal and distal ends. The fabricationof the cutting balloon assembly also includes providing an expandableballoon having a balloon proximal end and a balloon distal end. Theexpandable balloon is mounted on the catheter distal end. Thefabrication of the cutting balloon assembly also includes mounting thescoring mesh prepared as described above on the expandable balloon.

According to one embodiment, the mounting of the scoring mesh on theexpandable balloon includes connecting the scoring mesh to the balloonproximal and distal ends. The scoring mesh can be connected to thedelivery catheter after the balloon distal end and before the balloonproximal end in relation to an operator using the cutting balloonassembly.

For example, the mounting of the scoring mesh on the expandable ballooncan include winding at least one distal string around the balloon distalend and passing through openings in the distal filament loops, therebyto tie the distal filament loops of the scoring mesh to the balloondistal end. Likewise, the mounting of the scoring mesh on the expandableballoon can include winding at least one proximal string around theballoon proximal end and passing through the openings in the proximalfilament loops, thereby to tie the proximal filament loops of thescoring mesh to the balloon proximal end.

According to still another aspect of the present invention, there isprovided a method for a simulation of an optimal position for deploymentof a stent. The method includes providing a balloon assembly describedabove, in which the filaments of the scoring mesh are radiopaque. Thisballoon assembly is advanced, by using fluoroscopy, over a guidewirewithin the cardiovascular system of a patient so that to place theballoon adjacent a stenotic lesion inside a stenosed region. Then, theballoon is inflated and angiograms of the radioopaque scoring mesh aretaken. Further, the method includes processing and analyzing an image ofthe radioopaque scoring mesh on the angiograms so as to obtain theoptimal position for deployment of the stent.

There has thus been outlined, rather broadly, the more importantfeatures of the invention in order that the detailed description thereofthat follows hereinafter may be better understood. Additional detailsand advantages of the invention will be set forth in the detaileddescription, and in part will be appreciated from the description, ormay be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, embodiments will now be described, by way ofnon-limiting example only, with reference to the accompanying drawings,in which:

FIG. 1 illustrates a schematic longitudinal cross-sectional view of acutting balloon assembly, according to one embodiment of the presentinvention;

FIGS. 2A-B illustrate schematic longitudinal fragmentary views of thedistal portion of the cutting balloon assembly shown in FIG. 1,according to two embodiments of the present invention;

FIG. 3 shows a perspective view of an exemplary weaving jig suitable forpreparation of the scoring mesh, according to one embodiment of thepresent invention;

FIGS. 4A-4G show various embodiments of the pattern of the scoring meshof the present invention; and

FIG. 5 illustrates a schematic longitudinal fragmentary view of thedistal portion of the cutting balloon assembly shown in FIG. 1,according to a further embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The principles of the medical device according to the present inventionmay be better understood with reference to the drawings and theaccompanying description, wherein like reference numerals have been usedthroughout to designate identical elements. It being understood thatthese drawings which are not necessarily to scale, are given forillustrative purposes only and are not intended to limit the scope ofthe invention. Examples of constructions, materials, dimensions, andmanufacturing processes are provided for selected elements. Those versedin the art should appreciate that many of the examples provided havesuitable alternatives which may be utilized. Certain terminology is usedherein for convenience only and is not to be taken as a limitation onthe present invention. As used throughout this description, proximal anddistal orientation relationships are in relation to an operator (e.g.,interventional cardiologist/radiologist) utilizing the invention asdescribed herein.

Referring to FIG. 1, a schematic longitudinal cross-sectional view of adistal portion of a cutting balloon assembly 10 is illustrated,according to one embodiment of the present invention. It should beunderstood that the cutting balloon assembly 10 is not bound to thescale and proportion illustrated in FIG. 1 and in other drawings. Thecutting balloon assembly 10 is used to expand passageways in a patient'sblood vessel (not shown) by cutting blockages within the vessel. Ablockage may be a lesion, stenosis, plaque or any other infliction thatwould constrict a patient's vessel.

Generally, the cutting balloon assembly 10 includes a delivery catheter11, an expandable balloon 12, and a scoring mesh 13 disposed around theexpandable balloon 12. The delivery catheter 11 is in the form of anelongate tubular member and has a catheter proximal end 111, a catheterdistal end 112, and one or more catheter lumens 113 and 114 extendingbetween the catheter proximal and distal ends. According to theembodiment shown in FIG. 1, the delivery catheter 11 has an axial lumen114 located along a longitudinal axis (not indicated) of the deliverycatheter 11, and an exterior (or inflation/deflation) lumen 113 locatedabout the axial lumen 114. The axial lumen 114 is sized to accommodate aguidewire 14 that can be inserted therethrough along the longitudinalaxis of the delivery catheter 11. The inflation/deflation lumen 113 isused to establish fluid communication between the expandable balloon andexternal balloon inflation device (not shown). It should be noted thatalthough FIG. 1 shows a coaxial arrangements of wire guide lumen 114 andthe inflation/deflation lumen 113, when desired, the lumen for receivinga guidewire and the inflation/deflation lumen can be both positionedside-by-side within the delivery catheter, mutatis mutandis.

The delivery catheter 11 is a deflectable tube fabricated of arelatively stiff yet somewhat pliant material, which permits the deviceto be introduced into a patient's vascular system along a tortuous path.The delivery catheter 11 can be formed from plastic, metal, or compositematerials, e.g., a plastic material having a wire, braid, or coil core,which may prevent kinking or buckling of the delivery catheter 11 duringadvancement. Examples of materials suitable for the delivery catheter 11include, but are not limited to, polyurethane, polyimide, nylon,polyester or some other suitable biocompatible material.

The expandable balloon 12 is located at the catheter distal end 112 andhas a balloon proximal end 121, a balloon distal end 122, and aninterior cavity 123 located between the balloon proximal end 121 and theballoon distal end 122. As shown in FIG. 1, the expandable balloon 12 isdisposed circumferentially about the delivery catheter 11 at the distalend 112. The expandable balloon 12 is fixedly attached to the exteriorwall of the delivery catheter 11, by bonding, adhesion, ultrasonicwelding or any other suitable attachment technique to form aliquid-tight seal and communication between the balloon 12 and theexterior lumen 113 of the catheter 130. The expandable balloon 12 can,for example, be constructed from polyurethane, silicone or some othersuitable biocompatible material. A diameter of the balloon 12 can, forexample, be from about 4 to about 20 mm for use in the venous system,and from about 1.5 to about 12 mm for use in the arterial system.

The cutting balloon assembly 10 can also include a guiding catheter 15and a manipulator 16 of the guiding catheter 15. The guiding catheter 15of the cutting balloon assembly 10 can be in the form of a thin-walled,cylindrical flexible tube adapted to penetrate into a body passage (notshown) to reach the location of plaque or stenosis under treatment. Thedelivery catheter 11 is mounted within the guiding catheter 15, and canbe manipulated by the operator from the outside at the guidingcatheter's proximal end 151.

The guiding catheter 15 may be constructed from substantially flexible,durable, strong and/or floppy materials. For example, the guidingcatheter 15 can be made of a flexible, durable, strong plastic materialand/or plastic having a braid or other reinforcement (not shown) thatsufficiently supports the guiding catheter 15 to prevent kinking orbuckling, while allowing the guiding catheter 15 to be directed easilythrough tortuous vessel ducts. Examples of such plastic include, but arenot limited to, polyimide, polyvinyl chloride, nylon, teflon, etc. Theguiding catheter 15 can also be made of a composite material, such as awire mesh or a coil, (e.g., stainless steel coil). When desired, theguiding catheter 15 may be multi-layered with different materials inorder to provide a graduated bending and stiffness characteristic overits length.

The guiding catheter 15 includes a lumen 17 for housing the deliverycatheter 11. The lumen 17 has sufficient size for receiving the distalend 112 of the delivery catheter 11 therethrough together with theexpandable balloon 12 in the deflated condition.

The cutting balloon assembly 10 may include a handle 18 on the catheterproximal end 111 to facilitate manipulating the delivery catheter 11.When desired, the handle 18 can be integrated with the manipulator 16for manipulating the cutting balloon assembly 10 for delivering thescoring mesh 13.

As shown in FIG. 1, the cutting balloon assembly 10 can be equipped witha guide wire 14 that extends from a guide wire port 116 of the deliverycatheter 11 through the lumen 111 to an opening 115 arranged in a distaltip of the catheter distal end 112. As shown in FIG. 1, the guide wire14 also extends through the lumen 17 of the guiding catheter 15 andpasses through a guide wire port 152 arranged in the manipulator 16.

Referring to FIG. 2A, the scoring mesh 13 is disposed around theexpandable balloon 12 between the balloon proximal end 121 and theballoon distal end 122 and covers the expandable balloon 12. The scoringmesh 13 includes interlacing filaments 131 that interweave between amesh proximal end 132 and a mesh distal end 133 and have a cross-hatchedpattern. As a result of the interweaving, each of the filaments passesabove one or more other filaments and then under one or more otherfilaments, and vice versa.

According to an embodiment, the interlacing filaments 131 form one ormore permanent links with neighboring filaments between the meshproximal end and the mesh distal end. The permanent links are formed byintertwining a part of the filaments interweaving between the meshproximal end and the mesh distal end. The intertwining can, for example,be carried out by twisting one filament with another by one or moreturns and/or by twining one filament about another.

A concentration of the permanent links within the permanent linksdetermines a strength and flexibility of the mesh. Moreover, thepermanent links formed among the intertwining filaments 131 can maintainthe symmetry of the mesh pattern during the angioplasty procedure, sincethe permanent links can prevent the slippage of the filaments away fromtheir original contact points. The symmetry of the mesh pattern can bevisualized by a fluoroscope during angioplasty procedure so as tocontrol the treatment of plaque or stenosis and predict how a stent willfurther be positioned after removal of the cutting balloon catheter fromthe treated vessel. The distortion of the symmetry of the mesh patternvisualized by a fluoroscope may indicate, inter alia, the undulations ofthe inner surface of the vessel and the quality of the angioplastytreatment.

According to one embodiment, the interlacing filaments 131 form proximalfilament loops 134 at least at the mesh proximal end 132. According toanother embodiment, the interlacing filaments 131 form proximal filamentloops 134 at least at the mesh proximal end 132 along with distalfilament loops 135 at the mesh distal end 133. It should be noted thatprovision of filament loops at the mesh proximal and distal ends makesthe scoring mesh 13 less traumatic to the soft tissues of blood vesselsthan sharp ends of single wires. Moreover, as will be described below,the loops can facilitate attaching of the scoring mesh 13 to the cuttingballoon assembly 10.

The scoring mesh 13 can be connected to the ends of the expandableballoon 12 or to the delivery catheter 11 at one or more points.

According to one embodiment, the scoring mesh 13 is connected to theproximal and distal ends 121 and 122 of the expandable balloon 12.Specifically, the proximal filament loops 134 located at the meshproximal end 132 can be tied to the balloon proximal end 121, whereasthe distal filament loops 135 located at the mesh distal end 133 can betied to the balloon distal end 122. The loops 134 and 135 can be tied byone or more proximal strings 21 and distal strings 22 wound round theballoon proximal and distal ends 121 and 122, and passing throughopenings in the loops 134 and 135, correspondingly. Examples of thestrings suitable for fastening the loops include, but are not limitedto, cotton yarn 10-0 and/or stainless cord having a diameter in therange of about 0.025 mm to 0.075 mm.

Moreover, a medically-acceptable adhesive may also be used to secure orconnect the filament loops 134 and 135 of the scoring mesh 13 to theballoon proximal and distal ends 121 and 122, correspondingly. Examplesof such an adhesive include, but are not limited to, LOCTITE® 4011cyanoacrylate and LOCTITE® M-31CLT™ Hysol® Medical Device EpoxyAdhesive.

According to another embodiment, the mesh proximal end 132 can belocated on the delivery catheter 11 before the balloon proximal end 121,whereas the mesh distal end 133 can be located on the delivery catheter11 after the balloon distal end 122, in relation to an operator usingthe cutting balloon assembly 10. In this case, the scoring mesh 13 canbe connected to the surface circumference of the delivery catheter 11 atthe mesh proximal end 132 and the mesh distal end 133 (FIG. 2B).

The scoring mesh 13 can be tied to the delivery catheter 11 at the meshproximal end 132 before the balloon proximal end 121 in relation to anoperator using the cutting balloon assembly 10 by one or more proximalstrings 21 wound round the delivery catheter and passing throughopenings of the loops 134. Likewise, the scoring mesh 13 can be tied tothe delivery catheter 11 at the mesh distal end 133 after the balloondistal end 122 in relation to an operator using the cutting balloonassembly 10 by at least one distal string 22 wound round the deliverycatheter and passing through openings of the loops 135. Moreover, amedically-acceptable adhesive may also be used to secure or connect thefilament loops 134 and 135 of the scoring mesh 13 to the deliverycatheter 11. Alternatively, the filament loops 134 and 135 of thescoring mesh 13 can be soldered, brazed or welded to the deliverycatheter 11 at the joining portions before the balloon proximal end 121and after the balloon distal end 122.

In operation, the scoring mesh 13 does not prevent inflation of theballoon and can return to its original state after deflation of theballoon 12. The scoring mesh 13 and the regions in which the mesh isconnected to the delivery catheter 11 may have flexibility sufficientfor the cutting balloon catheter 10 to pass through the tortuousconfines of a vessel or other body lumens and do not damage them.

When desired, the filaments 131 of the scoring mesh 13 can have adimension and shape of the cross-section so as to incise a calcinatedand other hard stenosed region and to leave scores and grooves thereonduring the dilation procedure. Such grooves may facilitate a furtherpositioning of a stent at the scored place. For example, the filaments131 can each have a cross-sectional dimension in the range of about 0.01mm to about 0.5 mm, and preferably in the range of 0.05 mm to 0.2 mm.The cross-sectional shape and dimension of the filaments may vary fromwire-to-wire and/or along the lengths of each wire. The cross-section ofat least a part of the filaments can, for example, have a circularshape, oval shape, D-shape, rectangular shape, polygonal or any otherappropriate shape that can provide rather sharp edges that can incisecalcinated and other hard stenosed regions of the patient's blood vesseland to leave scores and grooves on the regions during the dilationprocedure. The outer periphery of the filaments may be formed with acenterless grinding process, laser cutting or by another suitable methodto provide a smooth profile, and desired shapes, tapers and changes indimension.

According to a further embodiment, the scoring mesh 13 can includescoring elements 23. The scoring elements 23 can, for example be formedby turns of the entwined filaments forming permanent links. Due toaggregation of two filaments together, these turns on a short piece oflength have a dimension that distinguishes from the dimension of asingle wire filament, and thereby they have scoring properties.

Likewise, scoring elements 23 can be dedicated elements attached to orplaced around the filaments forming the scoring mesh 13. Examples of thededicated elements forming the scoring elements include, but are notlimited to, ferrules with cutting edges placed around the filaments andblades attached to the filaments. As shown in FIGS. 2A-B, the dedicatedscoring elements 23 can, for example, be mounted in points ofintersection of the filaments, however other locations are alsocontemplated.

In operation, the scoring elements 23 can incise a calcinated and otherhard stenosed region and leave scores and grooves thereon during thedilation procedure. Such grooves may facilitate a further positioning ofa stent at the scored place.

The filaments utilized for the fabrication of the scoring mesh 13 can bemade of a material that is suitably biocompatible. Moreover, thefilaments utilized for the fabrication of the scoring mesh 13 can havethermo-mechanical shape memory and/or superelastic properties.

According to one embodiment of the invention, the filaments utilized forthe scoring mesh 13 are made of a metallic material. For example, themetallic material can be selected from a NiTi based alloy (e.g.,Nitinol), stainless steel and other materials possessing good shapememory, elastic or superelastic characteristics. According to anotherembodiment of the invention, the filaments are made of non-metallicmaterials, e.g. Capron, Nylon, etc.

According to a further embodiment of the invention, the filaments of thescoring mesh 13 are covered by an insulating layer. The insulating layercan, for example, be made of Teflon. The advantage of Teflon is itsthermal resistance and low coefficient of mechanical friction, whichleads to an additional reduction of traumatism.

Preferably, the filaments are radiopaque, so as to permit them to bevisualized by a fluoroscope with respect to a stenosed region in a bloodvessel. Thus, according to one embodiment, in order to provideradiopacity, the metallic material from which the filaments are made caninclude a material which provides radiopacity, e.g., a noble metal, suchas gold (Au), tantalum (Ta), platinum (Pt), etc. Likewise, the metallicmaterial can be alloyed with one or more metals selected from Pd, W, Nb,Co, Cu, etc.

According to another example, the filaments are made of a core tube(cannular strand) containing an axially disposed radiopaque material.

According to yet another example, the filaments can have radiopaqueparts of a predetermined length. These radiopaque filament parts canform at least a portion of the scoring mesh 13.

Radiopacity can also be improved through coating processes such assputtering or plating a radiopaque material onto the filaments, or thescoring mesh 13 fabricated from these filaments, thereby to provide aradiopaque coating layer on the filaments.

Likewise, radiopacity can yet be improved by using radiopaque markers(not shown) which can be attached to or placed around the filamentsforming the scoring mesh 13. In this manner, materials which have higherradiopacity than the mesh structure itself, such as gold, tantalum orplatinum, can be utilized as markers and be strategically placed alongthe body of the mesh to increase its visualization. For example, thescoring mesh 13 can comprise one or more radiopaque markers (not shown)attached to or placed around the filaments along the mesh length. Forexample, the radiopaque marker can be a ferrule put on the filament.

According to yet an embodiment of the invention, the filaments of thescoring mesh can include radiopaque coils having the predeterminedlength, which are put on a core wire in the desired locations along thewire length. In order to avoid slippage of the coils along the corewire, the coils can be welded, soldered and/or glued to the wire. Othermethods of binding the coils to the core wire can also be utilized.

According to still another embodiment of the invention, the filamentscan be multi-wire strands. In such a case, in order to improveradiopacity, the multi-wire strands can include a central core wire andat least one another wire twisted about said central core wire which ismade of a material having a level of radiopacity greater than the levelof radiopacity of said central core wire. Examples of such a materialinclude, but are not limited to, gold (Au), tantalum (Ta), platinum(Pt), etc.

The radioopaque scoring mesh can also provide a simulation of a possibledeployed stent, thus providing a possibility for analysis ofsub-optional deployment. In practice, once the balloon is inflatedwithin the cardiovascular system of a patient, the radio opaque scoringmesh angiograms are taken. The mesh can simulate a possible furtherdeployed stent. The image could then be processed and presented to thephysician to indicate optimal or sub-optimal deployment. A graph for astent diameter versus vessel wall diameter (as well as other parametersobtained from angiography while injecting contrast material, such asdistance between stent (struts) and vessel wall, and area, length andvolume of gap between the stent and vessel wall, etc.) can be analyzed.Such parameters and their analysis are known in the art and therefore isnot expounded hereinbelow.

In order to prevent restenosis, i.e., re-narrowing or blockage of ablood vessel at the site of a previous angioplasty, the scoring mesh 13or at least a part of it can comprise an active pharmacologic agent thatcan be delivered to a wall of the blood vessels scored or cut by thescoring mesh 13. A wide variety of active pharmacologic agents that caneffectively inhibit inflammation and smooth-muscle cell growth areknown. Examples of such pharmacologic agents include, but are notlimited to, antiproliferative agents (e.g., Sirolimus and Paclitaxeldrugs), immunomodulators, antithrombotics, and growth factor inhibitors.

The active pharmacologic agents may be provided on or within the scoringmesh 13 in a variety of ways. For example, the active agents may becoated over at least a portion of a surface of the filaments 131,typically by dipping, spraying, painting, plasma deposition,electroplating, ink jet coating, centrifuge systems or the like.

Likewise, the active substance may be incorporated in a coatingincluding a polymeric carrier. Examples of suitable polymeric carriersinclude, but are not limited to those comprising polylactic acids (PLA),polyglycolic acids (PLG), collagens, and the like. Alternatively, thepolymeric carrier may be a porous but non-resorbable material such asporous silicon or polyethylene. Hydrogels such as Poly Ethylene Oxide(PEO) may be used and release the drug through swelling and erosion. Thepolymer can coat the filaments 131 of the scoring mesh 13, oralternatively can create a film between at least some of the filaments131 or any combination of the above.

Having explained the structure of the cutting balloon assembly of thepresent invention, a method of manufacturing the assembly and thescoring mesh 13 will be described hereinbelow. The method begins fromproviding a predetermined number of filaments having predeterminedproperties, predetermined diameter and length.

According to one embodiment, the manufacturing of the scoring mesh iscarried out from one length of filament. According to anotherembodiment, the manufacturing of the scoring mesh is carried out fromseveral filaments. Various types of filaments suitable for the scoringmesh 13 are described above.

After providing the filaments, the process for the fabrication of thecutting balloon assembly includes weaving the scoring mesh from onelength of filament or from several filaments. According to oneembodiment of the present invention, at least a part of the preparationof the scoring mesh is carried out on a weaving jig (mandrel). FIG. 3shows a perspective view of an exemplary weaving jig 30 suitable forpreparation of the scoring mesh of the present invention. The weavingjig 30 has a cylindrical structure including a plurality of pins 31disposed circumferentially about the surface of the structure in rowsand extending outwardly therefrom. Generally, a dimension of the jig isdetermined by the dimension of the expandable balloon and can be foundeither empirically or calculated taking into account the dimension ofthe balloon.

However, if a dimension of the balloon is relatively small, e.g., 0.5mm-1 mm, then the dimension of the jig can be slightly greater than thedimension of the balloon, so it would be convenient a manual weaving ofthe mesh.

For example, a diameter of the weaving jig 30 can be in the range of 3mm to 4 mm (millimeters), whereas a length of the jig 30 can, forexample, be in the range of 30 mm to 40 mm. Each row of pins can, forexample, include between 10 and 14 pins having a diameter of about 0.4mm and a length of the protruded portion of about 2 mm. A number of therows can, for example, be about 25, and a distance between the rows canbe about 1.5 mm.

The method for fabrication of the scoring mesh of the present inventionfurther includes interlacing the filaments of the scoring mesh on thejig 30. Specifically, the filaments are placed between the pins andinterlaced to form a cross-hatched pattern. The interlacing includesinterweaving the filaments by passing each of the filaments above one ormore other filaments and under one or more other intersecting filaments,and intertwining a part of the filaments by twining one filament withanother and/or twining one filament about another filament to formpermanent links.

FIGS. 4A-4G show various embodiments of the pattern of the scoring meshof the present invention. Specifically, FIG. 4A shows a pattern 401 inwhich each ascending wire filament interweaves with all descendingfilaments and vice versa. Moreover, a part of the filaments areintertwined together to form permanent links.

For example, an ascending (from a left end toward a right end) filament41 goes first above a descending filament 42, then under a descendingfilament 43, then again above a descending filament 44, then again undera descending filament 45 and so on. On the other hand, a descendingfilament 46 goes first above an ascending filament 47, then under anascending filament 48, then again above an ascending filament 49 and soon. The rest of the filaments are arranged similarly. As shown in FIG.4A, a part of the interlacing filaments are twisted by one or more turnswith intersecting filaments, and thereby form rows 403 of permanentlinks 404 with neighboring filaments. Such permanent links 404 canprevent slippage of the filaments away from their original contactpoints during exploitation of the scoring mesh. The rows 403 can have apredetermined periodicity along the length between the mesh proximal anddistal ends, whereas the permanent links 404 can be arranged inpredetermined places between the mesh proximal and distal ends and. Thisenables a control of a flexibility of the mesh for maintaining the meshin the range of elastic deformations at stretching.

As shown in FIG. 4A, the interlacing filaments form filament loops 134and 135 at the mesh ends.

The scoring mesh having the pattern 401 includes scoring elements whichare formed by the turns of the twisted filaments forming the permanentcontacts 404. These turns have a dimension that distinguishes from thedimension of a single wire filament, and thereby they have scoringproperties.

It should be understood that when desired, dedicated scoring elements(not shown), e.g., ferrules with cutting edges, can be placed on thefilaments. The scoring elements can, for example, be placed around thefilaments forming the scoring mesh in points of intersection of thefilaments; however, other locations on the filaments are alsocontemplated.

FIG. 4B shows a pattern 402 in which the interlacing wire filaments areinterweaved in the vicinity of the mesh ends and are twisted in themiddle region of the mesh by one or more turns, thereby formingpermanent links in the middle region. Specifically, the wire filamentsare interlaced in regions 412 and 432 near the mesh ends, in the mannershown in FIG. 4A, whereas in a region 422, each ascending (from the leftend toward the right end) filament is twisted with one descendingfilament. At the mesh ends, the interlacing filaments form filamentloops 134 and 135.

FIG. 4C shows a pattern 403 in which the mesh includes a plurality ofself-twisted filament pairs 413 that are arranged in a parallelrelationship to each other and extend from one mesh end towards anothermesh end. At one or at both mesh ends, each of the self-twistedfilaments forms filament loops 134 and 135. The self-twisted filamentpairs 413 are interlaced by a plurality of intersecting filaments 423that can intersect the self-twisted filament pairs 413 at variousangles. The self-twisted filament pairs 413 can interweave and/orintertwine with the intersecting filaments 423. It should be noted thata mesh with such a pattern can withstand relatively large load duringstretching deformations. Moreover, a flexibility of a mesh with such apattern does not substantially differ in the flexibility of the patternformed entirely from interweaved filaments, i.e. without intertwining.This feature is especially important in the case when a ratio betweenthe diameter of the balloon in the inflated state and deflated state isrelatively big, for example, 8:1 or more.

FIG. 4D shows a pattern 404 in which the mesh is formed from a filament444 that extends from a mesh end 414 to another mesh end 424, where itforms a loop 434 and then returns to the original end 414. Themeandering behavior of the filament 444 continues as required, therebyforming a plurality of the loops 134 and 135 at both mesh ends,correspondingly. The meandering filament 444 is interlaced by aplurality of intersecting filaments 454 which can be interweaved and/ortwisted with the meandering filament 444.

FIG. 4E shows a pattern 405 in which the mesh includes a plurality offilament pairs 415 that are arranged in a parallel relationship to eachother and extend from one mesh end towards another mesh end. Filamentsin the filament pairs 415 are self-twisted at twisted regions 425A.Furthermore, the filament pairs 415 ramify between the twisted regions425A and form a region 425B of openings 435, and then converge back intothe twisted regions 425A. As shown in FIG. 4E, in the region 425B of theopening 435, each filament of the filament pairs 415 is twisted by oneor more turns with the filament of a neighboring filament pair. Each ofthe filament pairs forms filament loops 134 and 135 at one mesh end orat both mesh ends.

FIG. 4F shows a pattern 406 in which the mesh includes a plurality offilament pairs 416 that are arranged in a parallel relationship to eachother and extend from one mesh end towards another mesh end. Filamentsin the filament pairs 416 are arranged in regions of a first type 426and a second type 436. The filaments in the regions of the first type426 form openings 446, whereas the filaments in the regions of thesecond type 436 are self-interlaced in an 8-shaped form. As shown inFIG. 4F, in the opening 446, each filament of the filament pairs 416 istwisted by one or more turns with the filament of a neighboring filamentpair. Each of the filament pairs 416 forms filament loops at one meshend (as shown in FIG. 4F) or at both mesh ends.

When desired, the scoring mesh can be fabricated only on a part of theweaving surface of the jig (30 in FIG. 3). FIG. 4G shows a pattern 407in which a mesh 457 includes two pairs of filaments 417 and 427 whichare extended and self-interlaced between mesh ends 437 and 447. At themesh ends 437 and 447, at least one of the filament pairs forms filamentloops 134 and 135. When such a mesh is mounted on a balloon 51, it canbe wound around the balloon 51 as a band, as shown in FIG. 5.

After weaving, the process of mesh fabrication further includesannealing of the scoring mesh for memorizing and storing the mesh shapeand thereby imparting structural rigidity and dilatation ability to themesh. The parameters of the annealing depend on the materials of thefilaments and the method of heating. The annealing can be carried in onestep or in a few steps with consequent heating and cooling the mesh.

According to one embodiment, the annealing of the scoring mesh iscarried out in two stages. First, a preliminary annealing is carried onthe jig (30 in FIG. 3). Such a preliminary annealing treatment canrelieve the internal stresses in the material and provide memorizationof the mesh shape. A diameter of the expandable balloon (12 in FIG. 1)in the deflated state can, for example, be in the range of about 0.5mm-1 mm. Therefore, for convenience of the fabrication, a diameter ofthe cylindrical part of the jig can be greater than the diameter of theexpandable balloon (12 in FIG. 1) in the deflated state.

After heating, the mesh, which is mounted on the jig, is cooled andtaken off from the jig.

Then, the mesh having a dimension of the jig after the preliminaryannealing is stretched up to a diameter that is usually less than thediameter of the balloon in the deflated state, e.g., to the diameter ofabout 0.1 mm-0.2 mm.

Further, the stretched mesh is put on a mandrel having a diameter lessthat than the diameter of the deflated balloon, and fastened to themandrel by a string. The mandrel, can for example, be a piece of wiremade of steel, nickel-titanium alloy or any other suitable material. Thestring can, for example, be made from copper, a copper alloy (e.g.,Manganin™) or any other suitable material.

Then, a final annealing is carried out for the mesh placed on themandrel to provide final memorization of the mesh shape. A dimension ofsuch a mesh after the final annealing can be slightly less than thedimension of the deflated balloon so that the mesh, even with remainingdeformations, would be tightly fitted to the balloon after deflation.

It should be appreciated that the invention is not limited to thespecific implementation of the preliminary annealing and finalannealing. According to one embodiment, the heating is carried out byplacing the mesh mounted on the weaving jig in a furnace or consequentlyin various furnaces configured for this purpose. When the mesh isfabricated from a nickel-titanium alloy (e.g., Nitinol™), thepreliminary annealing and the final annealing can, for example, becarried out at a temperature of about 400° C.-600° C. for at least about10 min. After the heating, the mesh can be cooled to the roomtemperature. It should be understood that generally time of the thermaltreatment may be shorter or longer than 10 minutes, depending on theheating technique, jig mass, etc.

According to another embodiment, the heating is carried out by passing arequired electric current through the wire filaments that in this caseshould be made from at least partially electrically conducting material.For example, when the material of the mesh is Nitinol a current of about1 A (Ampere) to 3 A applied for about 2 sec to tens of seconds can beused.

After the final annealing, the scoring mesh is mounted on the expandableballoon (12 in FIG. 1) of the cutting balloon assembly (10 in FIG. 1).The mounting includes placing the scoring mesh on the balloon andconnecting the mesh to the ends of the expandable balloon 12 or to thedelivery catheter 11 at one or more points, as described above withreference to FIG. 1.

As such, those skilled in the art to which the present inventionpertains, can appreciate that while the present invention has beendescribed in terms of preferred embodiments, the concept upon which thisdisclosure is based may readily be utilized as a basis for the designingof other structures and processes for carrying out the several purposesof the present invention.

It should be understood that the snare of the present invention is notlimited to a medical treatment of a human body. It can be successfullyemployed for medical treatments of animals as well.

Also, it is to be understood that the phraseology and terminologyemployed herein are for the purpose of description and should not beregarded as limiting.

In the method claims that follow, alphabetic characters used todesignate claim steps are provided for convenience only and do not implyany particular order of performing the steps.

It is important, therefore, that the scope of the invention is notconstrued as being limited by the illustrative embodiments set forthherein. Other variations are possible within the scope of the presentinvention as defined in the appended claims. Other combinations andsub-combinations of features, functions, elements and/or properties maybe claimed through amendment of the present claims or presentation ofnew claims in this or a related application. Such amended or new claims,whether they are directed to different combinations or directed to thesame combinations, whether different, broader, narrower or equal inscope to the original claims, are also regarded as included within thesubject matter of the present description.

What is claimed is:
 1. A cutting balloon assembly, comprising: adelivery catheter having a catheter proximal end, a catheter distal end,and at least one catheter lumen extending between the catheter proximaland distal ends; an expandable balloon having a balloon proximal end anda balloon distal end, the expandable balloon mounted on the catheterdistal end; and a scoring mesh disposed around the expandable balloon,the scoring mesh having no self-expandable portions along an entirelength of the scoring mesh, and comprising interlacing filaments thatinterweave between a mesh proximal end and a mesh distal end, at leastone of the filaments interweaves between the mesh proximal end and themesh distal end, protrudes from the mesh distal end, bends upon itself,arrives back at the distal end of the mesh to form a distal filamentloop at the mesh distal end, and again interweaves between the meshproximal end and the mesh distal end after forming the distal filamentloop; at least one of the interlacing filaments interweaves between themesh proximal end and the mesh distal end, protrudes from the meshproximal end, bends upon itself, arrives back at the proximal end of themesh to form a proximal filament loop at the mesh proximal end, andagain interweaves between the mesh proximal end and the mesh distal endafter forming the proximal filament loop; and at least one of thefilaments intertwines with neighboring filaments to form permanent linksarranged in rows being not evenly spaced over the entire length of themesh, and at least a part of the rows being located on a cylindricalmiddle portion of the expandable balloon between two conical portions ofthe expandable balloon which are between the mesh proximal end and themesh distal end, wherein the scoring mesh includes scoring elementscorresponding to at least some of the permanent links on the cylindricalmiddle portion, the scoring elements having sharp edges that areconfigured to incise calcinated, fibrotic or other hard stenosed regionsof vessel walls.
 2. The cutting balloon assembly of claim 1, wherein thescoring mesh is connected to the balloon proximal and distal ends. 3.The cutting balloon assembly of claim 1, further comprising at least onedistal string wound radially around the balloon distal end and woventhrough openings in the distal filament loop, connecting the distalfilament loop of the scoring mesh to the balloon distal end.
 4. Thecutting balloon assembly of claim 1, further comprising at least oneproximal string wound radially around the balloon proximal end and woventhrough the openings in the proximal filament loop, connecting theproximal filament loop of the scoring mesh to the balloon proximal end.5. The cutting balloon assembly of claim 1, further comprising at leastone distal string wound round the delivery catheter after the balloondistal end in relation to an operator using the cutting balloonassembly, said at least one distal string passes through the openings inthe distal filaments loop, thereby to tie the scoring mesh to thedelivery catheter.
 6. The cutting balloon assembly of claim 1, furthercomprising at least one proximal string wound round the deliverycatheter before the balloon proximal end in relation to an operatorusing the cutting balloon assembly, thereby to tie the filaments at themesh proximal end to the delivery catheter.
 7. The cutting balloonassembly of claim 1, wherein the scoring elements are formed by twistedturns of the intertwined filaments forming said at least one permanentlink.
 8. The cutting balloon assembly of claim 7, wherein said twistedturns of the intertwined filaments forming said at least one permanentlink extend in a longitudinal direction of the balloon.
 9. The cuttingballoon assembly of claim 1, wherein the scoring elements are dedicatedelements attached to or placed around the filaments forming the scoringmesh.
 10. The cutting balloon assembly of claim 1, wherein the filamentsof the scoring mesh are radiopaque.
 11. The cutting balloon assembly ofclaim 10 configured for a simulation of an optimal position fordeployment of a stent.
 12. The cutting balloon assembly of claim 11,wherein the simulation comprises: advancing the balloon assembly, byusing fluoroscopy, over a guidewire within a cardiovascular system of apatient so as to place the balloon adjacent a stenotic lesion inside astenosed region; inflating the balloon; and taking angiograms of theradiopaque scoring mesh.
 13. The cutting balloon assembly of claim 12,wherein the simulation further comprises processing and analyzing animage of the radiopaque scoring mesh on the angiograms so as to obtainthe optimal position for deployment of the stent.
 14. The cuttingballoon assembly of claim 1, wherein at least a part of the scoring meshcomprises an active pharmacological agent that can inhibit inflammationand smooth-muscle cell growth.
 15. The cutting balloon assembly of claim1, further comprising a guiding catheter including a lumen for housingthe delivery catheter.
 16. The cutting balloon assembly of claim 1,further comprising at least one guide wire.
 17. The cutting balloonassembly of claim 1, wherein the permanent links are arranged in rowshaving a predetermined periodicity along the length between the meshproximal and distal ends.
 18. The cutting balloon assembly of claim 1,wherein at least one of the rows of the permanent links is separatedfrom an adjacent row of the rows of permanent links by a row ofintersections of filaments that interweave, the intersections offilaments that interweave not forming permanent links.
 19. A cuttingballoon assembly, comprising: a delivery catheter having a catheterproximal end, a catheter distal end, and at least one catheter lumenextending between the catheter proximal and distal ends; an expandableballoon having a balloon proximal end and a balloon distal end, theexpandable balloon mounted on the catheter distal end; and a scoringmesh disposed around the expandable balloon, the scoring mesh having noself-expandable portions along an entire length of the scoring mesh, andcomprising one continuous and monolithic length of wire that is woven toform interlacing portions that interweave between a mesh proximal endand a mesh distal end, at least one portion of the one continuous andmonolithic length of wire protrudes from the mesh distal end, bends uponitself and arrives back at the distal end of the mesh to form distalfilament loops at the mesh distal end; at least one portion of the onecontinuous and monolithic length of wire protrudes from the meshproximal end, bends upon itself and arrives back at the proximal end ofthe mesh to form proximal filament loops at the mesh proximal end; andat least one of the interlacing portions intertwines with neighboringinterlacing portions to form permanent links arranged in rows being notevenly spaced over the entire length of the mesh, and at least a part ofthe rows being located on a cylindrical middle portion of the expandableballoon between two conical portions of the expandable balloon which arebetween the mesh proximal end and the mesh distal end, wherein thescoring mesh includes scoring elements corresponding to at least some ofthe permanent links on the cylindrical middle portion, the scoringelements having sharp edges that are configured to incise calcinated,fibrotic or other hard stenosed regions of vessel walls.
 20. A cuttingballoon assembly, comprising: a delivery catheter having a catheterproximal end, a catheter distal end, and at least one catheter lumenextending between the catheter proximal and distal ends; an expandableballoon having a balloon proximal end and a balloon distal end, theexpandable balloon mounted on the catheter distal end; and a scoringmesh disposed around the expandable balloon, the scoring mesh not havingself-expandable portions along an entire length of the scoring mesh, andcomprising interlacing filaments that interweave between a mesh proximalend and a mesh distal end, at least one of the filaments interweavesbetween the mesh proximal end and the mesh distal end, protrudes fromthe mesh distal end, bends upon itself, arrives back at the distal endof the mesh to form a distal filament loop at the mesh distal end, andagain interweaves between the mesh proximal end and the mesh distal endafter forming the distal filament loop; at least one of the interlacingfilaments interweaves between the mesh proximal end and the mesh distalend, protrudes from the mesh proximal end, bends upon itself, arrivesback at the proximal end of the mesh to form a proximal filament loop atthe mesh proximal and again interweaves between the mesh proximal endand the mesh distal end after forming the proximal filament loop; and atleast one of the filaments intertwines with neighboring filaments toform permanent links arranged in rows being not evenly spaced over theentire length of the mesh, and at least a part of the rows being locatedon a cylindrical middle portion of the expandable balloon between twoconical portions of the expandable balloon which are between the meshproximal end and the mesh distal end, wherein the scoring meshcorresponding to at least some of the permanent links on the cylindricalmiddle portion, the scoring elements, the scoring mesh includingdedicated scoring elements that are attached to at least a portion ofone or more of the filaments at positions other than crossing points ofthe one or more filaments and that have sharp edges that are configuredto incise calcinated, fibrotic or other hard stenosed regions of vesselwalls.
 21. A cutting balloon assembly, comprising: a delivery catheterhaving a catheter proximal end, a catheter distal end, and at least onecatheter lumen extending between the catheter proximal and distal ends;an expandable balloon having a balloon proximal end and a balloon distalend, the expandable balloon mounted on the catheter distal end; and ascoring mesh disposed around the expandable balloon, the scoring meshhaving no self-expandable portions along an entire length of the scoringmesh, and comprising interlacing filaments that interweave between amesh proximal end and a mesh distal end, at least one of the filamentsinterweaves between the mesh proximal end and the mesh distal end,protrudes from the mesh distal end, bends upon itself, arrives back atthe distal end of the mesh to form a distal filament loop at the meshdistal and again interweaves between the mesh proximal end and the meshdistal end after forming the distal filament loop; at least one of theinterlacing filaments interweaves between the mesh proximal end and themesh distal end, protrudes from the mesh proximal end, bends uponitself, arrives back at the proximal end of the mesh to form a proximalfilament loop at the mesh proximal and again interweaves between themesh proximal end and the mesh distal end after forming the proximalfilament loop; and at least one of the filaments intertwines withneighboring filaments to form permanent links arranged in rows being notevenly spaced over the entire length of the mesh, and at least a part ofthe rows being located on a cylindrical middle portion of the expandableballoon between two conical portions of the expandable balloon which arebetween the mesh proximal end and the mesh distal end, wherein thescoring mesh includes scoring elements corresponding to at least some ofthe permanent links on the cylindrical middle portion, the scoringelements having sharp edges that are configured to incise calcinated,fibrotic or other hard stenosed regions of vessel walls, and the scoringelements are connected to both the proximal filament loop and the distalfilament loop.